Asaf Levy

Scientists have seen Asgard archaea crawling for the first time. When it comes to the origin of eukaryotes, this is like seeing a feathered dinosaur in the wild. (Video courtesy of Philipp Ralder)

Giant DNA viruses encode a hallmark translation initiation complex of eukaryotic life Giant DNA viruses encode a cap-binding complex homologous to eIF4F, the defining translation-initiation complex of eukaryotes. The viral cap-binding complex is required for viral protein synthesis and...

Cool finding:
Giant DNA viruses encode a hallmark translation initiation complex of eukaryotic life: Cell www.cell.com/cell/fulltex...

And to Debbie as well!

The Dead Sea

A nice spot to check exams

#ProtistsOnSky
no 'swimming' by 𝘝𝘢𝘮𝘱𝘺𝘳𝘦𝘭𝘭𝘢, definitively no 'staying still'. just a relaxed walk towards the lunch...

It is widely accepted that #T6SS -mediated intoxication occurs only on solid surfaces, where prolonged cell-cell interactions are forced, and not in liquid environments. But is this generalization true? Our new preprint says it isn't. A 🧵 ...
biorxiv.org/content/10.6...
🦠

Lab trip

@jbdsf.bsky.social

The Punchline One of the worst players in the NHL gets voted into the All-Star Game.

10 years ago today was one of craziest moments in world sports. The 2016 National Hockey League All-Star Game.

Listen to the great story over here wonderfully told by RadioLab @latif.bsky.social

www.wnycstudios.org/story/the-pu...

Multiple protein structure alignment at scale with FoldMason Protein structure is conserved beyond sequence, making multiple structural alignment (MSTA) essential for analyzing distantly related proteins. Computational prediction methods have vastly extended ou...

FoldMason is out now in @science.org. It generates accurate multiple structure alignments for thousands of protein structures in seconds. Great work by Cameron L. M. Gilchrist and @milot.bsky.social.
📄 www.science.org/doi/10.1126/...
🌐 search.foldseek.com/foldmason
💾 github.com/steineggerla...

Great new story from Sophie Helaine and Molly Sargen!

www.helainelab.com

Saw it. Very cool

thanks Itzik

congrats Aaron!

A great work by Nimrod Nachmias in collaboration with Feng Jiang.

Why it matters:
• Explains how eCISs recognize hosts and competitors
• Reveals a massive, untapped diversity of receptor binding proteins
• Enables programmable protein delivery systems

Take-home message:

eCIS specificity is driven by a modular, rapidly evolving fiber repertoire, anchored by conserved baseplate domains and decorated with swappable receptor-binding modules.

Targeting was inhibited by D-mannose, and mutations in predicted binding residues abolished activity.

This directly links fiber structure to glycan-dependent cell recognition.

We experimentally validated the concept.

A tail fiber from Paenibacillus was engineered into an eCIS system and showed highly specific targeting of human THP-1 monocyte-like cells, with no activity on other human cell lines.

Phylogenetic analysis shows many binding domains were likely acquired by horizontal gene transfer from eukaryotes (animals, plants, fungi) and viruses — not just bacteria.

This mirrors evolutionary strategies seen in phages and animal viruses.

Fiber domains resemble host and viral proteins involved in adhesion and immunity, including:
lectins, immunoglobulins, cadherins, C1q (a mammalian complement system componenet), and viral hemagglutinins.

These systems appear to use molecular mimicry for cell recognition.

Structure revealed what sequence could not.

Using AlphaFold and Foldseek, we identified:
• 276 distinct fiber architectures
• 1,177 structural fold families

One of the most diverse receptor-binding repertoires known!

Many eCIS operons encode multiple different tail fibers.

This suggests a single eCIS particle can be polyvalent — capable of targeting more than one cell type.

We identified five previously unknown N-terminal anchor domains (eBAP1–eBAP5) that attach fibers to the eCIS baseplate.

These domains define distinct evolutionary lineages of eCIS machines across bacteria and archaea.

We solved this by combining domain-based discovery with structure prediction.

📊 Outcome:
• 3,445 tail fibers
• 2,585 eCIS loci
• 1,069 microbial genomes

This is the first global catalogue of eCIS receptor-binding domains.

But how these systems recognize specific target cells has been a long-standing mystery.

Targeting is controlled by tail fibers, the receptor-binding proteins of eCISs.
They evolve extremely fast, making them nearly invisible to standard genome searches.

A new paper from the lab on virus-like particles called eCISs www.nature.com/articles/s41...

How bacteria evolved thousands of precision nanoinjectors?

Some bacteria don’t secrete toxins — they inject them using phage-derived machines called extracellular contractile injection systems (eCISs).

A good gene name for sure

Daniel Kordan is an amazing photographer